Hi Meghan
Thanks for posting on the community! If you are looking to change all of the shape's sizes colors and text size simply select the entire org chart instead of the individual employee shapes and change the formatting.

If you are looking to style these shapes individually you can select the multiple shapes by CTRL + click on each shape you would like to format.

You can also use our Conditional Formatting feature to set rules that would apply styling to certain shapes. To learn more take a look at the Conditional Formatting article in our Help Center.
As for styling the font of the 'role fields' you should be able to change these styles in the shape when you choose to show them.
If I misunderstood or did not completely answer your question please reach out again!